Chemical mechanical planarization pad with a release liner comprising a pull tab

ABSTRACT

A chemical mechanical polishing (CMP) pad with a release liner that has a pull tab is prepared by contacting the CMP pad to an adhesive layer with release liner. The adhesive layer sheet is cut along a first portion of a perimeter of the CMP pad. An extension of the adhesive layer is cut that extends beyond an edge of the CMP pad at the remaining portion of the perimeter of the CMP pad, thereby creating an extension of the adhesive layer sheet with the adhesive layer exposed. The exposed adhesive layer is cut to a depth not to extend into the release liner. The adhesive layer is removed from the exposed region leaving only the release liner pull tab as a continuous extension of the release liner material.

TECHNICAL FIELD

This disclosure generally relates to polishing pads used in chemical mechanical polishing, and more specifically to a chemical mechanical polishing pad with a release liner comprising a pull tab.

BACKGROUND

An integrated circuit is typically formed on a substrate by the sequential deposition of conductive, semi-conductive, and/or insulative layers on a silicon wafer. A variety of fabrication processes require planarization of at least one of these layers on the substrate. For example, for certain applications (e.g., polishing of a metal layer to form vias, plugs, and lines in the trenches of a patterned layer), an overlying layer is planarized until the top surface of a patterned layer is exposed. In other applications (e.g., planarization of a dielectric layer for photolithography), an overlying layer is polished until a desired thickness remains over the underlying layer. Chemical-mechanical planarization (CMP) is one method of planarization. This planarization method typically involves a substrate being mounted on a carrier head. The exposed surface of the substrate is typically placed against a polishing pad that is attached to a rotating platen. The carrier head provides a controllable load (e.g., a downward force) on the substrate to push it against the rotating polishing pad. A polishing liquid, such as slurry with abrasive particles, can also be disposed on the surface of the polishing pad during polishing.

SUMMARY

In order to perform planarization processes, the chemical mechanical polishing (CMP) pad must be physically attached to the platen of a CMP system. To achieve this attachment, the underside of the CMP pad may include a platen adhesive layer. A platen adhesive release liner, or release liner, may cover the platen adhesive to protect this platen adhesive during storage and transport of CMP pads until the time of their use. When a user wishes to attach a CMP pad to the platen, they must first remove the release liner. Previous release liners are the same shape (e.g., a circular shape) and can be difficult to remove from the underside of the CMP pad. In some cases, attempts to remove the release liner can result in damage to the CMP pad. CMP pads having multiple layers (e.g., a top polishing layer, a subpad layer, and any intermediate adhesive layers) may be particularly susceptible to damage during the removal of previous release liners. For example, certain combinations of pad layer materials may be susceptible to separation or delamination of the CMP pad layers when a conventional release liner is removed. This may be more problematic for CMP pads having interlayer adhesion strengths that are less than or at a similar magnitude to the adhesion strength between the release liner and the platen adhesive on the underside of the CMP pad. Furthermore, the additional bulk that results when a separate adhesive tape is added as a pull tab prevents efficient stacking of the pads, for example during shipping. The added bulk in a stack of pads can lead to deformities in the pad, which can result in damage and/or reduced performance of the pad.

This disclosure provides a technical solution to the problems of previous CMP pad release liners, including those described above, by providing a CMP pad having a protective release liner with a pull tab. This CMP pad is better adapted for easy removal of the protective release liner. The pull tab is an extension of the release liner that extends beyond the edge of the CMP pad (see, e.g., FIG. 2A, described below). The pull tab includes only the release liner layer from the platen adhesive side of the pad such that a user can conveniently grasp and use the pull tab in order to remove the release liner more easily without damaging the CMP pad to which it was attached. This disclosure further provides an efficient and reliable process for preparing such pull tabs. In this method, an extension of the adhesive layer is controllably prepared in the release liner attached to a CMP pad. Adhesive layer(s) are then removed from the extension, such that a pull tab is prepared on the release liner itself. In some cases, a controlled cut may be performed to facilitate the controlled removal of adhesive layers from the extension, such that only the release liner layer remains to form the pull tab.

In one embodiment, an article includes a chemical mechanical polishing (CMP) pad and a release liner. The CMP pad has a circular shape. The CMP pad includes a polishing layer and a platen adhesive layer. The release liner has a body portion and a pull tab. The body portion has substantially the same shape as the circularly shaped CMP pad. The body portion includes a release liner layer and an adhesive layer. The adhesive layer contacts the release liner layer of the CMP pad. The pull tab includes an extension of the release liner layer of the body portion that extends beyond an edge of the body portion (e.g., and beyond an edge of the CMP pad).

In another embodiment, a method of preparing a pull tab in a release liner contacting a CMP pad includes contacting the CMP pad to an adhesive layer of a sheet of the release liner. The sheet of the release liner includes the adhesive layer and a non-release liner layer. The method includes cutting the release liner sheet along a first portion of a perimeter of the CMP pad. The method includes cutting an extension of the release liner that extends beyond an edge of the CMP pad at the remaining portion of the perimeter of the CMP pad, thereby creating an extension of the release liner sheet with the adhesive layer exposed. The method includes contacting a surface to the exposed adhesive layer of the created extension of the release liner. The method includes removing the contacted surface from the exposed region, thereby removing the adhesive layer from the exposed region.

BRIEF DESCRIPTION OF FIGURES

To assist in understanding the present disclosure, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a diagram of an example system for chemical mechanical polishing/planarization;

FIG. 2A is a diagram of an example polishing pad with a release liner that has a pull tab;

FIG. 2B is a cross sectional view of a portion of the CMP pad and release liner of FIG. 2A;

FIG. 2C is a diagram of a perspective view of the polishing pad with pull tab release liner shown in FIG. 2A;

FIGS. 3A-3C are diagrams of various pull tab configurations for example release liners;

FIG. 4 is flowchart illustrating an example method of preparing a pull tab in a release liner of a chemical mechanical polishing pad;

FIGS. 5A-5D are diagrams illustrating various steps of the method of FIG. 4 ; and

FIG. 6 illustrates an example cutting guide for use in the example method of FIG. 4 ;

FIGS. 7A and 7B are diagrams illustrating a partial cut for improving the removal of exposed adhesive for preparing a pull tab.

DETAILED DESCRIPTION

It should be understood at the outset that, although example implementations of embodiments of the disclosure are illustrated below, the present disclosure may be implemented using any number of techniques, whether currently known or not. The present disclosure should in no way be limited to the example implementations, drawings, and techniques illustrated below. Additionally, the drawings are not necessarily drawn to scale.

As described above, previous release liner technology can be difficult to remove from a CMP pad without damaging the CMP pad. This disclosure recognizes that attaching a separate material to the release liner to aid in removal of the release liner is unreliable and can still result in damage to the CMP pad. The unique continuous pull tab of this disclosure (see, e.g., FIGS. 3A-C, described below) may facilitate the removal of a release liner from multilayer CMP pads (e.g., molded or casted CMP pads) having a top polishing layer, a subpad layer, and other adhesive layers. For example, if an adhesion strength between the top polishing layer, the subpad layer, and/or any intermediate adhesive layer is less than the adhesion strength between the release liner and the underside of the CMP pad, the different layers of the CMP pad may be inadvertently pulled apart or delaminated when the liner is removed. This disclosure satisfies the long sought need for an improved approach to removing a protective liner from the underside of a CMP pad in order to expose platen adhesive and attach the CMP pad to the platen of a CMP system without inadvertently damaging the CMP pad.

Chemical Mechanical Planarization System

FIG. 1 illustrates a polishing system 100 for performing chemical mechanical planarization. Polishing system 100 includes a chemical mechanical polishing (CMP) pad 102 (also referred to as a “chemical mechanical planarization pad” or a “polishing pad”) which is attached to a platen 104. For example, a platen adhesive layer (e.g., platen adhesive layer 216 of FIG. 2B) may be used to attach the CMP pad 102 to the platen 104. The CMP pad 102 generally has a circular or approximately cylindrical shape (i.e., with a top surface, a bottom surface, and a curved edge). The CMP pad 102 may be made of polyurethane or any other appropriate material along with any additives and/or filler materials. CMP pad 102 may have any appropriate thickness and any appropriate diameter (e.g., or radius 116 of FIG. 2A) to accommodate its use in polishing system 100. For instance, the thickness of a CMP pad 102 may range from about 0.5 millimeters to greater than 5 centimeters. The diameter (e.g., radius 116 of FIG. 2A) of the CMP pad 102 is generally selected to match or be just smaller than, the diameter of the platen 104 of the polishing system 100 used.

The platen 104 can generally be rotated during chemical mechanical planarization. A wafer 106 (e.g., a silicon wafer with or without conductive, semi-conductive, and/or insulative layers, as described above) is attached to a head 108 of a rotatable chuck. The wafer 106 may be attached using vacuum and/or a reversible adhesive (e.g., an adhesive that holds the wafer 106 in place during chemical mechanical planarization but allows the wafer 106 to be removed from the head 108 after chemical mechanical planarization). During CMP processing, a slurry 110 may be provided on the surface of the CMP pad 102 before and/or during chemical mechanical planarization. The slurry 110 generally includes a fluid and particles that may be abrasive and/or chemically reactive. A conditioner 112 is a device which is configured to condition the surface of the CMP pad 102. Conditioning of the surface prepares the CMP pad 102 to be used for chemical mechanical planarization. The conditioner 112 generally conditions the surface by contacting the surface of the CMP pad 102 and removing a portion of the top layer of the CMP pad 102 to improve its performance during chemical mechanical planarization.

In order for these and other CMP processes to proceed according to expectations for a given CMP pad 102, the structure of the CMP pad 102 should not be altered or damaged when the pad 102 is being attached to the platen 104. A release liner is provided on the CMP pad 102 to protect platen adhesive. The release liner is removed to expose the platen adhesive and allow a user to attach the CMP pad 102 to the platen 104. Using previous technology there was a risk of damaging the CMP pad 102 when the release liner was removed. This disclosure provides an improved release liner that includes a pull tab that is a continuous component of the release liner sheet or film, as described further below.

Example CMP Pads with a Release Liner Having a Pull Tab

FIGS. 2A and 2B show a CMP pad 102 with a release liner 218 that has a pull tab 202. FIG. 2A shows a top-side angled view of a CMP pad 102 attached to a release liner (liner layer 218 shown in FIG. 2B) with a pull tab 202 extending from the edge 114 of the CMP pad 102. The pull tab 202 generally facilitates the removal, by a user of the CMP pad 102, of the release liner layer 218, such that a platen adhesive layer 216 of the CMP pad 102 is exposed (see cross-section view of FIG. 2B). The CMP pad 102 may be any type of chemical mechanical polishing pad, such as a molded or casted pad. The CMP pad 102 may be formed of any appropriate materials for facilitating the planarization and/or polishing of a given substrate. For example, the CMP pad 102 may be made of polyurethane with or without additives and/or fillers. The CMP pad 102 may have any appropriate texture and/or patterning to facilitate planarization/polishing. The CMP pad 102 may have any appropriate size. For example, the radius 116 may be an appropriate size to use the CMP pad 102 in a given polishing system 100. The perimeter of the CMP pad 102 is the distance around the edge 114 of the CMP pad 102 and is given by 2πr, where r is the radius 116 of the CMP pad 102. The CMP pad 102 may have a single layer of a material or may be multi-layered, as shown in the example of FIG. 2B. Examples of CMP pads 102 include those prepared by casting, molding, coating, extruding, printing, sintering, spraying, and the like.

FIG. 2B shows a cross-section through line A-B of the various possible layers of the article 200 having a CMP pad 102 with attached release liner layer 218, including the pull tab 202. FIG. 2B illustrates the article 200 from a perspective view. FIGS. 2B and 2C are not drawn to scale. As shown in the example of FIG. 2B, the CMP pad 102 includes a top polishing layer 204, an adhesive layer 206, a subpad layer 208, and a release liner 210. The adhesive layer 206 attaches the polishing layer 204 to the subpad layer 208, and the platen adhesive layer 210, 218 release liner layer which protects the bottom surface of the CMP pad 102. In other embodiments, the CMP pad 102 may include more or fewer layers. For example, the CMP pad 102 may include a single polishing layer 204 or may omit one or more layers in some cases.

The polishing layer 204 may include polyurethane and/or any additives/fillers to improve polishing/planarization performance. The subpad layer 208 may be a foam or other more or less compressible layer. As an example, a subpad layer 208 may include polyurethane and any additives/fillers. The adhesive layer 206 generally includes any adhesive material(s) that can adhere to each of the connecting layers. For instance, adhesive layer 206 may include an adhesive material (e.g., glue, tape, etc.) that adheres to both the polishing layer 204 and the subpad layer 208. For instance, as shown in the example of FIG. 2B, adhesive layer 206 includes sublayers 206 a-c, where layer 206 a is a top pad adhesive, 206 b is a carrier film, and 206 c is a subpad adhesive. Similarly, the platen adhesive layer 210 may include any appropriate number of sublayers, as illustrated by the top adhesive layer 212, carrier film 214, and platen adhesive layer 216 in FIG. 2B. For instance, adhesive layer 212 includes an adhesive material (e.g., glue, tape, etc.) that adheres to both the subpad layer 208 of the CMP pad 102 and the carrier film 214, while the platen adhesive layer 216 includes the same or a different adhesive material (e.g., glue, tape, etc.) that adheres to both the carrier film 214 and the release liner layer 218. In some cases, the bottom adhesive layer 216 may be a platen adhesive that is an adhesive material (e.g., glue, tape, etc.) that can reliably adhere (e.g., with a high adhesion strength) to the platen 104 (see FIG. 1 ).

The release liner layer 218 includes the pull tab 202, which is an extension of the release liner layer 218 that extends beyond the edge 114 of the main body of the release liner 210 (e.g., edge 310 illustrated in FIGS. 3A-C) and the edge of the CMP pad 102 (e.g., edge 114 of FIG. 2A). The release liner layer 218 may be a polyester film. The pull tab 202 is an extension of the release liner layer 218 (e.g., from the body portion 302 of the example release liner configurations 300, 320, 340 of FIGS. 3A-C, described further below) without the adhesive layers 212, 216 and the carrier film layer 214.

As described further below, this disclosure recognizes that certain multi-layered CMP pads 102 may be particularly susceptible to damage (e.g., separation and/or delamination of layers) when conventional release liners are removed. For example, using previous technology, the CMP pad 102 may separate at the polishing layer 204, the subpad layer 208, and/or any of the other layers 206 and 210. The pull tab 202 of this disclosure significantly reduces or eliminates occurrence of this type of inadvertent damage.

Example Release Liner Configurations

FIGS. 3A-C show different example configurations 300, 320, 340 of release liners 210. The example configurations 300, 320, 340 show release liners 218 with different numbers, shapes, and sizes of pull tabs 202. The example of FIG. 3A shows a configuration 300 in which the release liner 218 includes a circular body portion 302 with a single semicircle-shaped pull tab 202 extending beyond the edge 310 of the body portion 302. The example of FIG. 3B shows a configuration 320 in which the release liner 218 includes a circular body portion 302 with multiple rectangle-shaped pull tabs 202 of different sizes extending beyond the edge 310 of the body portion 302. The example of FIG. 3C shows a configuration 340 in which the release liner 218 includes a circular body portion 302 with multiple semicircle-shaped pull tabs 202 of the same sizes extending beyond the edge 310 of the body portion 302. These example configurations 300, 320, 340 are not exhaustive. This disclosure contemplates release liners 218 having any number of pull tabs 202 (i.e., with one or more pull tabs 202), where the pull tabs 202 have any size or shape.

For each of the configurations 300, 320, 340 shown in FIGS. 3A-C, the release liner 218 includes a circular body portion 302 with one or more pull tabs 202. The pull tabs 202 are a continuous extension of the release liner layer 218 from the body portion 302, such that the body portion 302 and pull tabs 202 form a continuous sheet of material. The circular body portion 302 has a radius 308. The radius 308 is generally substantially the same as (e.g., within a threshold distance, such as a few millimeters, of) the radius 116 of the CMP pad 102 to which the release liner 218 is attached. As such the body portion 302 generally has substantially the same shape and size as the circularly shaped CMP pad 102.

For each of the configurations 300, 320, 340 shown in FIGS. 3A-C, the pull tabs 202 have a width 304 along the perimeter of the body portion 302 and a length 306 extending away from the body portion 302. The width 304 and length 306 may be any values that are appropriate for a given application. For example, the width 304 and length 306 may be selected to ensure a user is able to grasp the pull tab 202 in order to effectively remove the release liner 218 from the CMP pad 102 to which it is attached. In some embodiments, the width 304 and/or length 306 of the pull tabs 202 may be determined based at least in part on the size of the body portion 302 of the release liner 218. For instance, the width 304 and/or length 306 may be a predetermined fraction of a characteristic size (e.g., radius 308) of the body portion 302 of the release liner 218 (e.g., or on the size, such as radius 116, of the CMP pad 102 to which the release liner 218 is attached).

Example Methods of Preparing CMP Pads with a Release Liner Having a Pull Tab

FIG. 4 illustrates an example process 400 for preparing a CMP pad 102 with a release liner 218 that has a pull tab 202. The process 400 may begin with providing a CMP pad 102. The CMP pad 102 may have been prepared using any appropriate method, such as casting, molding, or the like. Characteristics of the CMP pad 102 are described in greater detail above with respect to FIGS. 1-2B.

At step 404, the CMP pad 102 is contacted to a sheet of the platen adhesive material (e.g., a sheet that includes the layers 212-218 illustrated in FIG. 2B but that is not yet transformed into a pull tab-containing release liner 218). In particular, the subpad layer 208 of the CMP pad 102 is contacted to the top adhesive layer 212 of the sheet of the release liner material. FIG. 5A shows a diagram 500 illustrating a CMP pad 102 that is contacted to a sheet 510 of the platen adhesive material. The CMP pad 102 is contacted to the sheet 510 such that the sheet 510 extends beyond the edge 114 of the CMP pad 102.

Referring to both FIGS. 4 and 5A, at step 406, a force 512 may be applied to the top surface of CMP pad 102 (e.g., to the polishing layer 204 of the CMP pad 102) and/or to the bottom surface of the sheet 510 of the release layer material (e.g., to the release liner layer 218). Force 512 may be applied manually or using any appropriate instrument, such as a laminator (e.g., to provide a controlled force 512). Application of force 512 may facilitate attachment of the CMP pad 102 (at subpad layer 208) to the sheet 510 of the platen adhesive material.

At step 408, the body portion 302 of the adhesive layer 510 (210) is cut from the sheet 510 (see FIGS. 3A-C for reference). Referring to the example of FIG. 5A, this may be achieved by cutting the adhesive layer sheet 510 along a first portion 504 of a perimeter of the CMP pad 102. This cutting may be performed using any appropriate cutting tool 502. The cutting tool 502 may be a knife or blade that is controlled manually or may be an automated cutting tool, such as a computer numerical control (CNC) cutting machine. Cutting may be performed manually (e.g., using any blade, knife, etc.) by cutting along the edge 114 of the CMP pad 102 or automatically by cutting at predefined positions using an automatic cutting tool 502. Cutting along portion 504 of the CMP pad's perimeter may be performed the entire way through the adhesive layer sheet 510 at a depth of 224 (see FIG. 2B). For example, referring to FIG. 2B, cutting along perimeter portion 504 may be performed to at least a depth 224, such that each layer 212-218 of the adhesive layer 510 is cut through entirely.

Referring to both FIGS. 4 and 5A, at step 410, an extension 514 is cut from the release liner sheet 510. The pull tab 202 may be formed by cutting the extension 514 of the adhesive layer 510 that extends beyond the edge 114 of the CMP pad 102 along path 508. Path 508 extends outward from the edge 114 of the CMP pad 102 along the remaining portion 506 of the perimeter of the CMP pad 102. As at step 408, cutting along path 508 may be performed all the way through the adhesive layer 510. For example, referring to FIG. 2B, cutting along path 508 may be performed to at least a depth 224, such that each layer 212-218 of the adhesive layer 510 is cut through entirely. In some cases, the extension 514 may be cut at the same time as portion 504, such that steps 408 and 410 are combined. In some embodiments, the extension 514 may be cut before the portion 504 is cut, such that step 410 is performed before step 408.

The extension 514 may be cut at step 410 manually or automatically using an automated cutting tool 502, as described with respect to step 408 above. In embodiments in which the extension 514 is cut manually, a cutting guide may be used. The cutting guide acts as a specialized stencil for cutting the extension 514 that will form the pull tab 202. An example cutting guide 600 is shown in FIG. 6 . The cutting guide 600 includes an extension surface 602, an alignment edge 604, a stabilizing surface 608, and an extension design edge 612. The extension surface 602 defines a shape of the to-be-cut extension 514 that will form the pull tab 202 (e.g., whether the extension 514 is semicircular as in FIGS. 3A, 3C, and 5A-D, rectangular as in FIG. 3B, or any other shape). For the example cutting guide 600, the extension surface 602 has a semicircular shape that extends a length 306 from the alignment edge 604. The alignment edge 604 is configured to align with the edge 114 of the CMP pad 102 (e.g., along the remaining portion 506 of the CMP pad's perimeter). The width 304 of the alignment edge 604 may be the same or similar to the width 304 of the to-be-cut extension 514 (see also FIGS. 3A-C). The height 606 of the alignment edge 604 may be similar to a height of the CMP pad 102. The stabilizing surface 608 is generally configured to rest on the top surface of the CMP pad 102 (e.g., the polishing surface 204 of FIG. 2A), such that the cutting guide 600 remains stable (i.e., does not inadvertently move) during its use. The width 610 of the stabilizing surface 608 may be any appropriate value to ensure the cutting guide 600 remains stable during its use. For example, the width 610 may be on the order of a centimeter or so. The extension design edge 612 is the surface along which a user cuts to form the extension 514 illustrated in FIG. 5A. Referring to both FIG. 5A and FIG. 6 , the extension 514 may be formed by contacting the alignment edge 604 of the cutting guide 600 to the edge 114 of the CMP pad 102 at the remaining portion 506 of the CMP pad's perimeter and manually cutting along the extension-design edge 612 to create a cut along path 508. Cutting may be performed at least to the depth 224 of FIG. 2B, such that the cut is entirely through all layers 212-218 of the adhesive layer sheet 510.

Returning to step 410 of FIG. 4 , in some embodiments, an additional cut may be performed along the remaining portion 506 of the CMP pad's perimeter to aid in the removal of adhesive layers 216, 212 and carrier film layer 214 of the platen adhesive layer material at steps 412-416. The length of the remaining portion 506 corresponds to the width 304 of the pull tab 202 (see FIGS. 3A-C), and this length may be based at least in part on the size of the CMP pad 102, as described above. The remaining portion 506 of the CMP pad's perimeter may be cut at a decreased depth (e.g., depth 226 of FIG. 2B), such that the release liner layer 218 is not cut at all or is at least not cut entirely through. This ensures that the pull tab 202 forms a continuous sheet of the release liner layer 218 (see FIGS. 2B and 2C). In some embodiments, cutting at steps 408 and 410, including cutting at a decreased depth 226 along the remaining portion 506 of the CMP pad's perimeter, may be performed using an automated cutting tool 502. For further illustration, FIG. 7A shows a cross sectional view 700 of the cutting tool 502 cutting through at least sublayers 212-216 of the adhesive layer (FIG. 7A), such that a cut 702 is made in these layers of the adhesive layer 210, as illustrated in subsequent view 710 of FIG. 7B.

FIG. 5B shows a diagram 520 of the CMP pad 102 with the cut extension 514 of the adhesive layer sheet 510 following the completion of step 410. The extension 514 includes all layers 212-218 of the adhesive layer material (see FIG. 2B) with the adhesive layer 212 exposed (i.e., pointing upwards in the view of FIG. 5B). Steps 412-416 facilitate the controlled removal of the adhesive layers 212, 216 and carrier film layer 214, such that only the pull tab 202 with release liner layer 218 remains. Referring to both FIGS. 4 and 5B, at step 412, a surface 522 is contacted to the exposed adhesive layer of the created extension of the adhesive layer. The surface 522 may be any appropriate material (e.g., a sheet of paper, a residual portion of the adhesive layer sheet 510, or the like).

FIG. 5C shows a diagram 530 illustrating the surface 522 after it is contacted to (e.g., adhered to) the extension 514. Referring to both FIGS. 4 and 5C, at step 414, a force 534 may be applied to the surface 522 in order to facilitate attachment between the surface 522 and the exposed adhesive layer 212 of the extension 514. At step 416, the surface 522 is removed, as illustrated by the arrow in FIG. 5C. When the surface 522 is removed, the adhesive layers 212, 216 and carrier film layer 214 are carried along with it, such that only the release liner layer 218 remains. FIG. 5D shows a diagram 540 illustrating the final CMP pad 102 with a release liner 218 that has a pull tab 202. The removed layers 212, 214, and 216 from the cut extension 514 are attached to the surface 522 that was removed at step 416 (FIG. 5B).

The unique pull tab 202 achieved via process 400 and that is a continuous extension of the release liner layer 218 that is also protecting the platen adhesive layer 216 of the CMP pad 102 may aid in preventing or eliminating damage to the CMP pads 102 when the release liner layer 218 is removed. The release liner layer 218 with pull tab 202 may particularly prevent damage to CMP pads 102 that have interlayer adhesion strengths (e.g., between the layers 204-208 of the CMP pad 102) that are less than the adhesion strength between the platen adhesive 212 on the underside of the CMP pad 102 and the release liner layer 218. This pull tab 202 that is formed as a continuous extension of the release liner layer 218 that protects the CMP pad 102 also facilitates improved storage and transportation of sets of CMP pads 102. For example, CMP pads 102 having release liners 218 with continuous pull tabs 202, as described in this disclosure, can be evenly or flatly stacked together without risk of damage. In contrast, if a separate pull tab were attached to the release liner, CMP pads would not stack evenly against each other. Instead, the added pull tabs would cause the CMP pads to stack at an angle relative to each other, resulting in an increased risk of damage during storage and transport.

Modifications, additions, or omissions may be made to the systems, apparatuses, and methods described herein. The components of the systems and apparatuses may be integrated or separated. Moreover, the operations of the systems and apparatuses may be performed by more, fewer, or other components. The methods may include more, fewer, or other steps. Additionally, steps may be performed in any suitable order. Additionally, operations of the systems and apparatuses may be performed using any suitable logic. As used in this document, “each” refers to each member of a set or each member of a subset of a set.

Herein, “or” is inclusive and not exclusive, unless expressly indicated otherwise or indicated otherwise by context. Therefore, herein, “A or B” means “A, B, or both,” unless expressly indicated otherwise or indicated otherwise by context. Moreover, “and” is both joint and several, unless expressly indicated otherwise or indicated otherwise by context. Therefore, herein, “A and B” means “A and B, jointly or severally,” unless expressly indicated otherwise or indicated otherwise by context.

The scope of this disclosure encompasses all changes, substitutions, variations, alterations, and modifications to the example embodiments described or illustrated herein that a person having ordinary skill in the art would comprehend. The scope of this disclosure is not limited to the example embodiments described or illustrated herein. Moreover, although this disclosure describes and illustrates respective embodiments herein as including particular components, elements, feature, functions, operations, or steps, any of these embodiments may include any combination or permutation of any of the components, elements, features, functions, operations, or steps described or illustrated anywhere herein that a person having ordinary skill in the art would comprehend. Furthermore, reference in the appended claims to an apparatus or system or a component of an apparatus or system being adapted to, arranged to, capable of, configured to, enabled to, operable to, or operative to perform a particular function encompasses that apparatus, system, component, whether or not it or that particular function is activated, turned on, or unlocked, as long as that apparatus, system, or component is so adapted, arranged, capable, configured, enabled, operable, or operative. Additionally, although this disclosure describes or illustrates particular embodiments as providing particular advantages, particular embodiments may provide none, some, or all of these advantages.

The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better explain the disclosure and does not pose a limitation on the scope of claims. 

What is claimed is:
 1. An article, comprising: a chemical mechanical polishing pad having a circular shape, the chemical mechanical polishing pad comprising a polishing layer; and a release liner comprising: a body portion having substantially the same shape as the circularly shaped chemical mechanical polishing pad, wherein the body portion comprises a release liner layer and an adhesive layer, wherein the adhesive layer is in contact with the chemical mechanical polishing pad; and a pull tab comprising an extension of the release liner layer of the body portion that extends beyond an edge of the chemical mechanical polishing pad.
 2. The article of claim 1, wherein: the body portion further comprises: a carrier film layer contacting the adhesive layer; a secondary adhesive layer contacting the carrier film layer; and the release liner layer is contacting the secondary adhesive layer.
 3. The article of claim 2, wherein the pull tab comprises the extension of the release liner layer of the body portion without the adhesive layer, carrier film layer, and the secondary adhesive layer.
 4. The article of claim 1, wherein the release liner layer of the body portion and the pull tab form a continuous sheet of material.
 5. The article of claim 1, wherein the release liner layer comprises one of a polyester film, kraft paper, or any other material protecting the adhesive layer.
 6. The article of claim 1, wherein the pull tab has a semicircular shape.
 7. The article of claim 1, wherein the pull tab has a rectangular shape.
 8. The article of claim 1, wherein the pull tab is configured to decrease occurrence of damage to the chemical mechanical polishing pad when the release liner layer is removed from the chemical mechanical polishing pad.
 9. The article of claim 1, further comprising a plurality of pull tabs, each pull tab comprising an extension of the release liner layer of the body portion that extends beyond the edge of the body portion.
 10. The article of claim 1, wherein the pull tab comprises a width along the edge of the body portion and a length directed away from the edge of the body portion, wherein the width and length are a predefined fraction of a characteristic size of the chemical mechanical polishing pad.
 11. A method for preparing a pull tab in a release liner for a chemical mechanical polishing pad, the method comprising: providing the chemical mechanical polishing pad; contacting the chemical mechanical polishing pad to a sheet of adhesive material, the sheet of the adhesive material comprising an adhesive layer and a release liner layer; cutting the sheet of adhesive material along a first portion of a perimeter of the chemical mechanical polishing pad; cutting an extension of the adhesive material that extends beyond an edge of the chemical mechanical polishing pad at the remaining portion of the perimeter of the chemical mechanical polishing pad, thereby creating an extension of the adhesive material with the adhesive layer exposed; contacting a surface to the exposed adhesive layer of the created extension of the adhesive material; and removing the contacted surface from the exposed adhesive layer, thereby removing the adhesive layer from the extension of the release liner and forming the pull tab.
 12. The method of claim 11, wherein a length of the remaining portion of the perimeter of the edge of the chemical mechanical polishing pad is a predefined fraction of a characteristic size of the chemical mechanical polishing pad.
 13. The method of claim 11, further comprising, before contacting the surface to the exposed adhesive layer, cutting along the remaining portion of the perimeter of the chemical mechanical polishing pad at a decreased depth such that the release liner layer is not cut through along the remaining portion of the perimeter of the chemical mechanical polishing pad.
 14. The method of claim 11, wherein steps of cutting the adhesive material along the first portion of the perimeter of the chemical mechanical polishing pad and cutting the extension of the adhesive material are performed using an automated cutting tool.
 15. The method of claim 11, wherein the pull tab is configured to decrease occurrence of damage to the chemical mechanical polishing pad when the release liner layer is removed from the chemical mechanical polishing pad.
 16. The method of claim 11, wherein cutting the adhesive material along the first portion of the perimeter of the chemical mechanical polishing pad comprises manually cutting along the edge of the chemical mechanical polishing pad.
 17. The method of claim 16, wherein cutting the extension of the adhesive material that extends beyond the edge of the chemical mechanical polishing pad comprises: providing a cutting guide comprising an alignment edge configured to align with the edge of the chemical mechanical polishing pad and an extension-design edge defining a shape of the to-be-cut extension of the adhesive material; contacting the alignment edge of the cutting guide to the edge of the chemical mechanical polishing pad at the remaining portion of the perimeter of the chemical mechanical polishing pad; and manually cutting along the extension-design edge of the cutting guide.
 18. The method of claim 11, further comprising, prior to removing the contacted surface from the exposed adhesive material, applying force to the surface.
 19. The method of claim 11, wherein the release liner layer is a polyester film, kraft paper, or other material protecting the adhesive material.
 20. The method of claim 11, wherein: the chemical mechanical polishing pad comprises a polishing layer and a subpad layer; and an adhesion strength between the polishing layer and the subpad layer is less than an adhesion strength between the subpad layer and the adhesive layer of the adhesive material. 